Time differential perturbed gamma gamma directional correlation measurements in the decay of 207Bi

Gamma-gamma directional correlation studies have been carried out on the 1063.62 - 569.67 KeV cascade in the decay of 207Bi using the time differential PAC technique. The measurements show the dependent perturbation of the correlation. From the plot of A2(t-) t-, the value of the relaxation parameter and the unperturbed expansion coefficient obtained after accounting for the finite time resolution and split angle corrections are lambdasub(2) = (2.4 +- 0.3) x 109 sec-1, A2(0) = 0.25 +- 0.016. From the lambda-value, the integral attenuation coefficient G2(00) has been estimated to be G2(00) = 0.69 +- 0.03. The differential data at various angles were integrated and the solid angle corrected integral coefficient obtained is A2(00) =0.204 +- 0.003. This attenuated A2(00) value is also indicative of the perturbation of the correlation which is contrary to the results obtained by Korner et al. (author)